This invention relates generally to loudspeakers, and more particularly to a crossover or a frequency response shaping system for adjusting the frequency response of a subwoofer that, in conjunction with a main speaker, produces the sonic output.
As is well known, a loudspeaker receives an electrical signal representing an audio sound, and converts the electrical signal to an audio sound wave via a loudspeaker driver unit. The driver unit comprises, in part, a motor that responds to the electrical signal to move a diaphragm. The movement of the diaphragm perturbs the surrounding air, which causes the audio wave.
Due to inadequate low-frequency characteristics, many loudspeakers do not respond well to input signals of very low frequencies (i.e., the bass or lower register). Thus, a high quality audio system may include a separate, specialized speaker, termed a subwoofer, which is designed to more accurately reproduce the lower frequencies of the full sound spectrum. This subwoofer may be used to reproduce the low-frequency portion of the same signal that is provided to the main speakers. In these applications, it is usually desirable to restrict the frequency range reproduced by the subwoofer to a range that is not reproduced by the main speakers. Further, it is desirable that the frequency and phase response characteristics of the subwoofer be adjustable so that the outputs of the subwoofer and the main speaker will combine in a desirable way (e.g., to produce a uniform frequency response). Thus, the response characteristics of the subwoofer is intended to complement the response characteristics of the main speaker, hence, achieving a desirable blending of the sonic output (i.e., sound) of the main speaker and the subwoofer. Unfortunately, subwoofer controls normally lack the capacity to properly adjust the output to achieve a subwoofer response that will complement the main speaker response.
In light of these problems, there is a need in the art for a subwoofer response determining system (commonly referred to as a crossover) that produces a proper blending of the subwoofer sonic output and the main speaker sonic output.
The present invention provides a system and method for accurately reproducing audio sounds by adjusting the response characteristics of a subwoofer to produce a proper blending of sound from a subwoofer and a main speaker in a sound reproduction system.
In architecture, the system comprises a compensation circuit configured to produce a desired low-frequency signal from an input signal in response to user adjustable settings that are indicative of main speaker response characteristics. The desired low-frequency signal, when cascaded through the subwoofer amplifier and the subwoofer, produces a subwoofer sonic output that, when combined with the main speaker sonic output, produces a more desirable blending of high-frequency and low-frequency sounds (i.e., a higher quality sound).
In accordance with another aspect of the present invention, a method is provided for accurately producing audio sounds by adjusting the low-frequency sonic output of a subwoofer. In the method, a desired low-frequency signal is produced in response to user adjustable settings that are indicative of main speaker characteristics. The desired low-frequency signal is produced by subtracting a signal indicative of the main speaker response from a signal indicative of the desired combined subwoofer-main speaker response.
Other systems, methods, features, and advantages of the invention will be or become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within the scope of the invention, and be protected by the accompanying claims.